1. Field of the Invention
The present invention relates to the technical field of a bumper structure adapted to be attached to a front end of a vehicle.
2. Description of the Background Art
Generally, a vehicle, such as an automobile, is equipped with a bumper attached to a front end thereof to serve as a means to absorb a shock, and a front grille disposed above a central region of the bumper and formed with an opening for introducing radiator-cooling air into an engine compartment. The bumper and front grill are designed with the emphasis on aesthetic quality, because they serve as a face defining each vehicle's personality.
In this connection, Japanese Patent Laid-Open Publication No. 11-314552 discloses a structure designed to allow a bumper to be attached to a front grill formed separately from the bumper in such a manner as to prevent the grill from being damaged even if an impact force acts on the bumper rearward.
In some cases, for the purpose of reduction in production cost and improvement in aesthetic quality, a bumper and a front grill are integrally formed as a single-piece component, instead of being formed as discrete components. In these cases, they are generally formed as a single-piece component through an injection molding process using synthetic resin. When a bumper and a front grill are formed separately from one another, the bumper is typically made of a resin material having a relatively low rigidity, such as PP (polypropylene), in view of shock-absorbing performance, and the front grill is typically made of a resin material having a relatively high rigidity, such as ABS (acrylonitrile-butadiene-styrene) resin. In contrast, when a bumper and a front grill are integrally formed as a single-piece component, the bumper and the front grill are made of a resin material having a relatively low rigidity, to guarantee a function of the bumper as a shock-absorbing means. In this case, if a fin member as one of aesthetic elements integrally formed in the grill to extend horizontally in such a maimer as to bridge across an air-intake opening of the grill, the fin member is likely to be bent downward by its own weight before being cooled and solidified after completion of an injection molding process to cause a problem about deterioration in appearance of the grill and in aesthetic quality of the entire component serving as a vehicle's face.
For example, as measures against this problem, it is conceivable to employ a structure designed such a fin support is integrally formed in the fin member to extend vertically from the fin member, and an extended end of the fin support is connected to another fin member or an edge of an opening of the grill disposed adjacent vertically thereto. While this structure can prevent the problem about bending of the fin member, the fin support as a non-aesthetic element exists within the opening of the grill together with the fin member as an aesthetic element. The existence of the non-aesthetic fin support causes a new problem about deterioration in appearance of the grill and in aesthetic quality of the entire component serving as a vehicle's face.
Particularly in a front grill designed to have a small number of fin members so as to achieve a simple appearance, the fin support becomes highly visible, or the above problem becomes serious.